We propose to carry out an epidemiological study of treated alcoholics to estimate the number who, five to ten years after treatment, have been social drinkers for at least three years. We intend to describe the nature of the drinking of ex-alcoholics and to compare their drinking with that of normal social drinkers who have never had any problems with alcohol. Further, assuming that such cases exist, we will attempt to find correlates of social drinking in order to indicate which individuals seen in treatment are likely to be able to become social drinkers. We will also seek to describe the environment in which social drinking can persist and the methods the ex-alcoholics use to maintain their ability to drink socially. We will describe the various types of drinking patterns we find in formerly treated alcoholics. Because alcoholics may be inaccurate reporters of their own drinking behavior, we will confirm these reports by interviewing a relative most likely to know their drinking behavior. We will also try to systematize their self-observation by asking them to keep a diary for two weeks, and we will experiment with observation of their drinking behavior in artifical but "natural" appearing settings. The alcoholic subjects will be a consecutive series of 1,000 ex-patients who were released from hospital inpatient or outpatient treatment at least five years previously, and who received a diagnosis of primary or secondary alcoholism at the time of that admission. We will review the subsequent inpatient and outpatient records of these patients, dividing the population into two groups: those with no records of having received additional psychiatric or medical treatment for alcoholism or its complications within these facilities in the past three years, and those who do have such a record. We will locate and personally interview a random sample of the latter group and all of the former group. For those who on self-report meet our criteriea for social drinking for all of the past three years, we will also interview a close family member and survey all subsequent treatment records to confirm their report. For those in whom the self-report of social drinking is confirmed, we will locate and interview an age and sex matched control living in the same city block as the subject. We will invite social drinking ex-alcoholics and their controls to participate in a pilot observational study of their drinking behavior.